Chapter 6 Flashcards
In order to understand cognitive development in infancy, we need to understand…
motor development
It is important to recognize typical development in order to be able to recognize …
deviance (progression or regression)
Most newborn infants exhibit _______ and ______ movements.
- spontaneous
- reflexive
Toddler movements = _____, while Infancy,childhood movements =
- motor milestones
- gross motor movements become more refined
In newborns, some movements seem ______ and without _____, and appear without any apparent ______.
- undirected
- purpose
- stimulation
Often times, newborns move in a specific way every time they are ______ in a certain place.
touched
Infants are born with _____ that seem to slowly disappear as they age. They move with _____ actions that tie into _____ _____ and _____ ____ later on in life.
- reflexes
- discrete
- motor milestones
- intentional movement
Newborn movement classified into 2 general categories:
- random/spontaneous movements
- infantile reflexes
Spontaneous movements
- infants’ movements that occur without any apparent stimulation
- seem very different from walking, reaching
Examples of spontaneous movements:
- squirm
- thrust legs or arms
- stretch fingers and toes
Supine =
laying on back
Supine kicking:
spontaneously thrust their legs when in supine position
Supine kicking is associated with what motor milestone?
walking
Through analysis of position, timing, and muscular activity, they found that supine kicking is…
- rhythmical
- kicks have a coordinated pattern
- ankle, knee, and hip joints move cooperatively, not independently
Supine kicking resembles _____ and _____ of an adult walking step.
- positioning
- timing
How does supine kicking differ from walking?
- infant’s timing is more variable from kick to kick
- infants tend to move joints in unison rather than in sequence
- cocontraction for infants while adults alternate
Cocontraction:
infants tend to activate both the muscles for flexing the limb (flexors) and the muscles for extending the limb (extensors)
In regards to supine kicking, by the end of the first year, infants..
- begin to move hip, knee, ankle sequentially
- both alternating and synchronous kicks after 6 months
- developing more ways of coordinating 2 limbs
Newborn’s spontaneous arm movements show well-coordinated ______ of _____, _____, and _____ joints.
- extension
- elbow
- wrist
- finger
Spontaneous arm movements are not as _____ and ______ as leg kicks.
- rhythmical
- repetitive
Early arm thrusts are not identical to adult reaching movements, as it takes infants several months to…
begin opening their fingers independently of the other joints in anticipation of grasping objects
Arm spontaneous movements appear to be influenced by _____ constraints.
environmental
Rhythmic flapping of arms, kicking of legs have been termed ______, because of …
- stereotypes
- the underlying temporal structure of the movements
Other stereotypes of newborn movements:
- head and face (eg. head banging)
- fingers (eg. flexing fingers)
Stereotypes suggest that newborns may be…
- weak
- unable to produce intentional, precise, goal-directed movements
Unlike random movements, infantile reflexes are…
- involuntary movements that an individual makes in response to a specific stimuli
- sometimes these responses occur only when the body is in a specific position
- stereotypical movement response to a specific stimulus
- only seen during infancy
3 types of infantile reflex:
- primitive reflexes
- locomotor reflexes
- postural reactions
Primitive reflex:
involuntary response to a specific stimulation that is often mediated by lower brain centres
Generally, newborns exhibit ____ reflexes at birth. These reflexes tend to lose their strength over time until they disappear around ____ months.
- strong
- 4
Primitive reflexes vs. spontaneous movements:
Reflexes:
- Responses to specific external stimuli
- Specific, often localized
- Same stimulus will elicit a specific reflex over and over again
Spontaneous movements:
- Do not result from any apparent external stimuli
- Non specific, generalized
Primitive reflexes examples:
- palmar grasp
- asymmetric tonic neck reflex
Postural reactions aka
gravity reflexes
Postural reactions help the infant _______ maintain posture in a changing ______.
- automatically
- environment
Postural reactions generally appear after the infant is ___ months old.
2
By late in ____ year, these isolated postural reactions ____ ____ of their repertoire of movements.
- first year or early in second year
- drop out
Locomotor reflex:
- Appears similar and related to a voluntary movement
- Appear much earlier than the corresponding voluntary behaviours
- Typically disappear months before the infant attempts the voluntary locomotor skill
3 locomotor reflexes:
- stepping
- swimming
- crawling
Primitive reflexes start to weaken or become modified after about ___ weeks, when infants learn to _____ their reflexes and ____ the movement outcome.
- 2
- adapt
- modify
Those who work with infants sometimes use a ____ __ _____ _____ and _____ to assess an individual infant’s development.
pattern of reflex appearance and disappearance
If the reflexes appear and disappear at an age close to the average, they consider the infant’s development _____.
typical
Deviation from the typical pattern and typical execution may occur in 2 ways:
- exhibiting a reflex when the individual should not
- not exhibiting a reflex when the individual should
A reflex that persists well after the average age of disappearance may indicate…
a pathological cerebral condition
Nonexistent or very weak response on one side of the body compared with the other could reflect…
a pathological condition
Babinski test:
- running a probe along the bottom of the foot
- used to check for neurological problems in patients with head injuries
- normal = toe flexion
Positive sign in babinski test:
- babinski reflex as seen in infancy has returned
- patient most likely has injury to the CNS
- toes pull upward instead of flexing
Why do we have to be careful when attempting to assess the neurological status of an infant?
- one infant may continue exhibiting reflexes without any pathological condition being involved
- most infants are ahead or behind the average ages
- difficult to establish exact time reflex disappears
- reflexive responses are very sensitive to environmental conditions
Several reflexes appear as soon as…
2-3 months in utero
3 Roles of reflexes:
- structural
- functional
- applied
Structural role of reflexes:
- Views reflexes as a byproduct of the human neurological system
- Reflexes reflect the structure of the nervous system
- The way humans are wired
- Consider reflexes at birth, nothing past
Functional role of reflexes:
- Reflexes exist to help the infant survive (eat, breathe, grasp)
- Fetus uses reflexes to position itself for birth, assist in the birthing process
Applied role of reflexes:
- Examine the role of reflexes in future volitional movements
- Different ideas depending on the theoretical viewpoints of researchers
What did McGraw (1943) believe?
Believed in motor interference theory: that infants could not move voluntarily until reflexes had been inhibited by the CNS
What was Zelanzo’s (1972) experiment?
- Experiment challenged the notion that reflexes and voluntary movements are not related
- Elicited stepping reflex daily in a small number of infants during first 8 weeks
- Result: Increased stepping reflex
- Result: Earlier onset of voluntary walking
- Concluded that involuntary walking reflex could be transformed into voluntary walking
Zelando (1972) proposed that…
- disappearance of reflex was due to disuse
- The period of reflex inhibition before onset of voluntary skill is necessary
- Systematic stimulation of a locomotor reflex could enhance infants’ acquisition of voluntary locomotion
Thelen (1983-1991) questioned…
whether reflexes had to be inhibited before voluntary movement could occur
Thelen proposed that…
Other constraints, rather than strictly maturation, may be related to the disappearance of the stepping reflex
In Thelen’s research, she noticed that infants have a dramatic increase in ___ ____ (primarily from ____) during the first 2 months of life. What does this mean?
- leg weight
- fat
- corresponding increase in muscle strength
- May cause the stepping reflex to disappear because infant has insufficient strength to lift now heavier legs
- Strength may be a rate limiter for stepping after 2 months or so of infancy
What did Thelen do in her experiment?
- ankle weights on infants to mimic weight gain resulted in reflex stepping decreasing
- put older infants (no longer reflex stepping) in water (buoyant, mimics strengths) = steps with greater frequency, results similar to Zelazo
- infants who did not reflexively step at 7 months did step when held over a treadmill
Thelen concluded that…
several individual constraints (rather than simply maturation) play a strong role as rate limiters on movement patterns during infancy
An infant does not suddenly acquire a complex skill, they must…
- Must learn to coordinate and control the interacting parts of their body
- Needs to attain certain fundamental skills that lead to skilled performance
Motor milestone:
- A fundamental motor skill
- Attainment which is associated with the acquisition of later voluntary movements
- landmark or turning point in motor development
Order in which an infant attains motor milestones is ______ _____, although ____ differs among individuals.
- relatively consistent
- timing
Bayley and Shirley claimed _____ pattern of skill acquisition can be related to _____ ____ in _____ constraints that occur typically in developing infants.
- progressive
- predictable changes
- individual
Bayley and Shirley’s progressive pattern of skill acquisition:
- maturation of CNS
- development of muscular strength and endurance
- development of posture and balance
- improvement of sensory processing
WHO: MGRS:
- multicentre growth reference study group (MGRS)
- secular trend of milestones does not exist
- Infants are currently attaining motor milestones at about the same age as infants did more than 80 years ago
- Observation techniques used by Bayley and Shirley were valid and reliable
_____ defined parental handling practices can alter the rate at which an infant attains motor milestones.
culturally
First child syndrome:
- cultural phenomenon in US
- moms hold their babies for long periods and avoid putting the infants on their stomachs for a long time
- results in delayed onset of certain motor milestones such as crawling
Carbetta and Bojczyk showed that…… can act as a rate limiters for other skills.
attainment of milestones themselves
Carbetta and Bojczyk studied:
- Hand preferences
- Once certain motor milestones were achieved, infants changed their hand preference and even reverted back to earlier forms of reaching (2 hands after walking)
- likely for balance = rate limiter
Although ______ exists in the acquisition of milestones, _____ ____ in several milestones may indicate a _____ _____.
- variability
- substantial delay
- developmental problem
How can Down syndrome be detected with delay of milestones?
- hypertonia = lack of muscle tone = delayed acquisition of milestones (lots of milestones require strength = rate limiter)
- floppy
- often improves in later development
Delays in milestones lead to delays in ….
the attainment of fundamental motor skills (ex. walking, ADLs, eating)
Infant mobility is important to early development, meaning any condition that _____ or _____ infant mobility may negatively affect _____ development.
- delays
- impedes
- cognitive
Motor development and early movement influence both ____ and _____ development.
- social
- cognitive
Some movements help create ____ pathways to the brain. This is critical in the first ___ years of life.
- neural
- 3
Part of learning is discovering ____-_____ relationships in surroundings.
cause-effect
Independent locomotion provides infants and toddlers with…
- a way to control and explore their environment
- socially interact
Many of the motor milestones of the first year of life involve the attainment of certain _____.
postures
Once infants can maintain a certain posture, they are ______.
balancing
Moving room technique:
- Seeing responses of babies in the middle of a room when the walls were moving
- EMG
- Visual information and the kinesthetic information were in conflict
- Reacted to the visual information rather than the kinesthetic information
- Responded as if their bodies were swaying and activated muscle to regain their starting posture
What did Bertenthal, Rose, and Bai do?
- observed variety of babies in moving room at 2 different speeds
What was found in the moving room experiment?
- visual info more than kinesthetic info
- action linked to movement speed
- responses improved with experience
- standing infants sway or fall while adults can keep their balance
- newly standing children take longer than adults to use postural muscles and attain stability
… is not the rate-controlling factor in infant posture and balance.
visual perception of self motion
Rate controlling factor for posture control may be coupling of the _____ _____ with the appropriate _____ _____.
- sensory information
- appropriate response
Once refined, _____ -______ couplings provide very sensitive and rapid adjustments to the _____.
- perception-action
- environment
Infants move = _____ change = infant must regulate and refine their movements based on…
- environments
- continuous sensory information
As systems develop and change, the _____ coupling must change as well to recalibrate to the _____.
- sensorimotor
- environment
Barela, Jeka, and Clark studied touch control in infants as they reached 4 stages:
- pulling to stand
- standing alone
- beginning to walk
- reaching 1.5 months of walking experience
In Barela, Jeka, Clark study, in the first 3 stages the infants responded to body sway by…
applying force to the surface
In Barela, Jeka, Clark study: after infants gained walking experience, they used _____ ____ to control posture rather than simply react to ____.
- touch information
- sway
_______ info plays a important role in posture and balance.
somatosensory
